1) Get rid of everything - number, emails, anything she bought you, pictures... throw them away
2) be prepared for the pain - if you loved her it will hurt. the first week will be worst, be prepared and accept it when it comes.
3) resist the urge to call, text, or email.
4) you will enevitably think about her, when she comes into your head, just gently push those thoughts away.
6) Understand that it will take time
7) Understand that eventually you will meet someone equally nice or better, and be over her
If you follow these rigidly - within 5-6 weeks you will begin to feel normal again. Its the holding on and 'bargaining' part (ie " if only i had of done this or that") which makes it difficult to move on. Some people stay in that zone for years... not healthy
Good luck!